选择中国，显示中国各省份，选择浙江省，显示浙江省下各县市。在注册时多会看到这种联动形式的表单，drupal cck中也可以使用这个效果，下面这篇文章详细讲述了过程。英文且很长，没耐性的可以直接使用这个模块: http://drupal.org/project/hierarchical_select
Dependent dropdowns —depdrops in short— are SELECT form elements which are linked. A classic example is a system of three SELECTs: country, state (or province), and city. When the user chooses a country, the SELECT for the state is updated to show all the states in that country. Likewise, when the user now chooses a state, the SELECT for the cities is updated to show all the cities in that state. More examples exist; lecturers and courses in a university is another example for linked SELECTs. Incidentally, some elements in the chain don't have to be SELECTs: product number, postal code, course number —these may be TEXTFIELDs.